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    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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<body>
    
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<script>
    //  JS基本数据类型
    //  string number  boolean  null undefined           object(array)


    // 隐式类型转换
    // ++ -- 的隐式类型转换  (> >=  < <=  ==  !=   注意: === !== 一般不会参数隐式类转换)
    // 其他数据类型遇到 ++ 和 -- 也会先隐式转化为数字类型,再自增或自减


    var a = "10";
    console.log(a++);
    console.log(a);

    var a = "hello";
    console.log(a++);
    console.log(a);

    var a = true;
    console.log(a++);
    console.log(a);

    var a = null;
    console.log(a++);
    console.log(a);

    var a = undefined;
    console.log(a++);
    console.log(a);


</script>
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